Evaluation of Test Methods for Determining the Resistance of Concrete to Chloride-Ion Penetration
L. Jiang, M. H. Zhang, and V. M. Malhotra
Appears on pages(s):
chloride; diffusion; fly ash; lightweight aggregate; metakaolin; migration; rice husk ash; silica fume; slag; test method
This paper presents results of a study that compared ASTM C 1202 test, a steady-state migration test, a conductivity test, and a non-steady-state diffusion test for deter-mining the chloride-ion penetrability of control portland cement concrete and concretes incorporating fly ash, ground granulated blast-furnace slag, silica fume, metakaolin, and rice-husk ash. The water-to-cement ratios of the control portland cement concretes ranged from 0.31 to 0.60. The content of fly ash and slag was 20, 40, or 60% by mass of total cementitious materials as cement replacement. Silica fume, metakaolin, and rice-husk ash was used as 8% cement replacement. Most of the concrete mixtures were made from normal-weight aggregate except for two concrete mixtures that were made from light-weight aggregate. In general, the results from the four test methods led to similar conclusions regarding the penetration of chloride ions into concrete. Therefore, ASTM C 1202 test method can be used for evaluating the resistance to chloride-ion penetration for concrete with or without supplementary cementing materials in spite of its short comings. The conductivity test is another rapid and convenient method, and has potential for wide acceptance by the construction industry for determining ingress of chloride ions into concrete.